Disconnection Using Tactical Sets of Functional Group-Keyed Transforms

3 Disconnection Using Tactical Sets of Functional Group-Keyed Transforms 

Retrosynthetic analysis can often be enhanced by strategies built around tactical combinations of PG-keyed transforms which together produce molecular simplification in a coordinated (but subtle) way. The concept of tactical combinations of transforms and a few examples of such combinations have been described in Section 2.10. The use of FG-keyed tactical combinations may be illustrated by a selection of specific applications. 

Target 162 cannot be directly simplified. However, it contains the full retron for the FG-keyed tactical combination which converts it to precursor 163 and thence to simple molecules. 3 Obviously, this approach requires that information on such tactical combinations be available in a form which facilitates its use. 

The retrosynthetic simplification of 164 which has just been outlined was initiated by the application of a [3,3] sigmatropic rearrangement transform. Other tactical combinations involve the use of such rearrangement transforms to link a pair of disconnective transforms. 

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